Combustion type unit heater



March 6, 1956 R. c. HAUCK ET AL 2,737,173

COMBUSTION TYPE UNIT HEATER Filed Aug. 11, 1953 2 Sheets-Sheet l A A Z /0 6 K QQQQQQQQO" Fig.3. O O O Q 0 O; O O

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COMBUSTION TYPE UNIT HEATER Filed Aug. 11, 1953 2 Sheets-Sheet 2 IN VEN TORS R0) 0. /-/A UCK BY ALBERTLA/AT/f/IN WSW. ,4 7'7ORNEV Unite States Patent COMBUSTION TYPE UNIT HEATER Roy C. Hauclr, Plainsboro, and Albert L. Nathan, Trenton, N. L, assignors to Delta Heating Corporation, Trenton, N. 3., a corporation of New iersey Application August 11, 1953, Serial No. 373,604

Claims. (Cl. 126-110) This invention relates to self contained heating devices of the type generally referred to as unit heaters and is directed particularly to constructions which may be readily and economically installed in substantially any location.

Unit heaters are ordinarily provided with a casing having a blower mounted thereon for directing air through the casing and over heating elements located in the casing.

However, when the air passing through the casing is heated by electrical resistance elements, the cost of operation is frequently prohibitive. On the other hand, when the heating elements are in the form of tubes or coils supplied with steam or hot water, it is necessary to provide a boiler or water heater from which supply and return pipes ex- Fig. 3 is a top plan view of the construction shown in Figs. 1 and 2 with a portion of the casing broken away;

Fig. 4 is a perspective illustrating a preferred type of combustion chamber employed in the construction of Figs.

Fig. 5 is a diagrammatic illustration of an alternative arrangement of the elements employed in a unit heater embodying the present invention; and

' Fig. 6 illustrates a portable unit embodying the present invention.

In that form of the invention chosen for purposes of illustration in Figs. lto 4 of the drawings the device is provided with an outer'casing 2 having a top 4, a bottom 6 and opposite side walls 8 and 10. The rear of the casing is provided with a cover plate 12 having a central opening 14 therein and a fan or blower 16 is supported by brackets 18 on the cover plate in position to direct air through the opening 14 and into the casing 2. The front of the casing is provided with a cover plate 20 on which louvers 22 are mounted for controlling and directing the flow of heated air issuing from the casing.

The sides 3 and 10 of the casing are provided with lower openings 24 and 26 and upper openings 28 and 30, respectively. An oil or gas burner 32 of any suitable or conventional type may be mounted adjacent any one of p the openings 24, 26, 28 and for discharging fuel, 'or a tend the unit. The system therefore is expensive to install and becomes substantially permanent and is not capable of installation in many locations or on portable mountings. In accordance with the present invention, these objections and limitations inherent in constructions of the prior art are overcome and unit heaters are provided which are self contained and economical to install and operate. Moreover, they are capable of use in substantially any location and can be readily moved from one position to another as circumstances require.

These results are preferably attained by providing the unit with a casing carrying a blower and having heating elements therein which are fired by a conventional fuel burner. The construction is unique in that it is especially suitable for use with a conventional oil burner although it is capable of use just as well with any of various types of gas burners. This result is attained by the provision of a special type of combustion chamber and means to permit the burner, draft regulator, and chimney or vent pipe to be variously arranged for flexibility in arrangement and convenience of installation.

The principal object of the present invention is to decrease the cost of producing, installing and operating unit heaters.

I Another object of the invention is to provide a novel type unit heater designed to be fired by an oil or gas burner.

A further object of the invention is to provide a unit heater with a casing, burner, heating elements and vent connection capable of various arrangements to simplify the installation thereof.

Another object of the invention is to provide a unit heater which may be arranged on a movable support for use as a portable heating device.

These and other objects and features of the present invention will appear from the following description thereof in which reference is made to the figures of the accompanying drawing for the purpose of indicating the nature of the present invention.

In the drawing: 1

'Fig. 1 is a vertical sectional view through a typical form of unit heater embodying the present invention;

Fig. 2 is a vertical sectional view taken on the line 2-2 of Fig.1;

mixture of fuel and air, into the casing. Ina similar manner a vent pipe 34 and a draft regulator 36 may be connectedto any of the openings in the casing to insure flow of the products of combustion to a chimney or exhaust under the proper draft. In the construction shown in Fig. 1 the fuel burner 32 discharges into thelower opening 24 in the side wall 8 of the'casing 2, the draft regulator 36 is located in the upper opening 28 of the side wall 8, whereas the vent pipe 34 is connected to the upper opening 31 in the opposite side wall 10 of the casing.

A combustion chamber 33 islocated within the casing in position to receive the fuel, or the mixture of fuel and air, issuing from the burner 32 and serves to provide sufficient combustion space to insure proper mixing and burning of the fuel and air for eflicient combustion. For most light-weight and economical construction the combustion chamber is preferably formed of stainless steel or other durable sheet metal but it may be lined with refractory or formed entirely of refractory material if desired.

As shown in Fig. 4, the combustion chamber is preferably cylindrical in form and provided with an open side 4%) communicating with a lower header or heat exchanging chamber 42 which surrounds the combustion chamber. Heating tubes 44 extend from the heat exchanging chamber 42 to an upper header 46 and are positioned in staggered relation or otherwise in the path of air being forced through the casing from the rear to the front thereof. The number, size and spacing of the heating tubes 44 will of course vary with the size of the unit, the type of fuel used and the desired velocity of air flow through the casing, but in any case, should be designed for efficient transfer of heat to the air flowing over the same.

The upper header 46 communicates at its opposite ends with opening 28 in which a draft regulator 36 is located and opening 39 to which a vent pipe 34 is connected for carrying off the products of combustion. The adjustrnents of the fuel burner 32 and draft regulator 36 are coordinated in a conventional manner to maintain the desired velocity of flow of the burning fuel-air mixture and products of combustion through the heating tubes. and other elements of the device to insure efficient combustion and efiicient heat exchange with the air directed through the casing 2 by the fan 16.

The heat exchanging chamber 42 is provided with means such as the brackets or legs 48 which serve to support the combustion chamber 38 in spaced relation with the Walls of the heat exchanging chamber and in alignment with the opening 24 with which the burner 2 communicates. The opposite ends of the combustion chamber are formed with spaced longitudinally extending projections 59 which hold the end of the combustion chamber in spaced relation with respect to the adjacent wall of the heat exchanging chamber. Further, the combustion chamber is provided at each end with inwardly extending projections 52 which serve as a seat engageable by the target 54 at the inner end of the combustion chamber toward which the fuel from the burner 32 is projected.

The target 54 is of smaller diameter than the combustion chamber so that flame and products of combustion may issue from the combustion chamber into the heat exchanging chamber through passages about the target as indicated at 56. Further, the products of combustion may flow from the opposite end of the combustion chamber adjacent the burner 32 through the openings 58 between the projections which space the combustion chamber from the adjacent end of the heat exchanging chamber. The openings in the casing such as the opening 24 through which the blast tube 5t) of the oil burner 32 extends are substantially larger than an ordinary blast tube and maybe, say, 6 inches in diameter. A sleeve 62 is mounted within the casing and communicates at its inner end with the combustion chamber 38. When an oil burner is used the blast tube extends into the sleeve 62 and the outer end of the sleeve is closed by the burner mounting flange 64. The space be tween the sleeve and blast tube serves as a relief or expansion chamber and the buffer effect thereby afiorded, especially in combination with the relief aiforded by the openings 56 and 58 at opposite ends of the combustion chamber, reduces vibration and baffling noises of the fuel and air jet and the roar of the combustion within the unit. The combination thus acts as a muffler for dampening or quieting the action of the burner during operation.

When it is desired to use a gas burner of either the draft induced or blower type, the opening 24 is large enough to permit a conventional burner to be mounted by an attaching flange and allow for the air inlet opening about the burner for draft or blower induced air supply to the combustion chamber. The unit thus may be fired by any desired type of burner and can be converted from oil to gas at will.

The target 54 is held in place by the rods 66 carried by a closure member 68 mounted in the lower opening 26 of the side wall opposite to the burner 32. The closure 68 preferably is provided with a clean-out door 70 which is normally held closed by the fastener 72 but is movable to permit access to the heat exchanging chamber and combustion chamber when desired. if desired the side wall of the casing about the opening 26 may be made removable as shown at 74 to permit access to the heat exchanging chamber and combustion chamber for cleaning or replacing. The end 76 of the heat exchanging chamber may then be removably secured in place by bolts 73 or the like, as shown in Fig. l.

The closure member 68 and the fuel burner 32 are interchangeable in position and the combustion chamber can be shifted from one side to the other so as to be located adjacent either the opening 24 or the opening 26. The unit therefore may be fired from the right or left side as required or most convenient in any particu lar installation. In a like manner, the vent pipe 34 and the draft regulator 36 may be interchanged in positions for the greatest flexibility and convenience in installation.

Moreover, as shown in Fig. 5, the casing and the elements within can be arranged horizontally for directing heated air downward instead of horizontally if preferred or necessary in any case. The front plate of the assembly may then be provided with diffusing means 80 such as an anemostat or the like. The location of the burner, pipe and draft regulator may be interchangeably positioned in the two openings in such an assembly for the most convenient and economical arrangement in any particular location.

In whatever arrangement the elements are assembled the blower l6 directs air from the room or an outside source over the heating tubes 44 and throughout the casing 2 about the heat exchanging chamber 42 and the header for discharge from the front of the casing past the louvers 22 or diffusing means 30. The louvers may of course be opened and directed as desired to insure the most effective heat exchange and distribution of the air issuing from the heater.

The fuel and air projected into the combustion chamher are provided with adequate space for efficient combustion in and about the combustion chamber and as they flow through the heat exchanging chamber and heating tubes to the header 46. In passing from the header 46 to the vent pipe 34 the draft is regulated by the regulator 36 in a conventional manner for insuring the most efficient combustion and heat transfer to the heating tubes 44 and the air propelled through the casing by the fan 16.

The casing for the unit is provided with mounting bolts as shown at 82 in Fig. l by which the unit may be suspended from a ceiling or other overhead. support. Further, the casing is provided with lower bolts 84 which extend through the bottom of the casing for mounting the unit upon a floor or other horizontal support or for securing the unit within a crate or shipping case. When mounted for horizontal use as shown in Fig. ,5 brackets or hangers 86 may be secured in place by the bolts 82 and 84 or other supports or mounting means may be used as desired.

As shown in Fig. 6 the unit of the present invention may be mounted on a portable support such as a hand truck or dolly for movement to any desired location in a warehouse, loading platform or elsewhere. In such cases the unit is secured to the truck by bolts 84 and the burner may be supplied with oil or bottled gas from a full tank 87 mounted on the casing or truck. An electric cord 88 supplies current to the blowers ignition means for the burner in such constructions and can be connected to any convenient light socket or plug.

While the construction and arrangement of the combustion chamber, heat exchanging chamber and heating tubes illustrated is preferred, it will be apparent that these elements may each be changed in form, cross-section and arrangement as well as their relative positions within the casing. Furthermore, any type of air diffusing means and any preferred mounting for the unit may be provided. In view thereof it should be understood that the particular embodiments of the invention shown in the drawing and described above are intended to be illustrative only and are not intended to limit the scope of the invention.

We claim:

1. A unit heater comprising elements formed for alternative assembly to permit installation of said heater in any of various locations, said heater including a casing having a pair of oppositely disposed openings in the side walls thereof, an open ended combustion chamber located in said casing and positioned adjacent a selected one of said openings, a fuel burner positioned to discharge fuel through said selected one of said openings and into the adjacent end of said combustion chamber, a target located adjacent the opposite end of said combustion chamber, holding means located in the opposite opening in said casing and holding the combustion chamber in position adjacent the opening into which the fuel burner discharges, and holding the target in said opposite end of the combustion chamber, heating elements for receiving products of combustion from the combustion chamber, and means for passing air to be heated through said casing and in heat exchanging relation to said heating elements, said openings being of similar size and shape and said fuel burner and holding means being alternatively mountable in said openings.

2. A unit heater comprising a casing having a pair of oppositely disposed openings in the side walls thereof, a combustion chamber located in said casing between said openings, a fuel burner positioned to discharge fuel through one of said openings and into said combustion chamber, means for holding the combustion chamber in position adjacent the opening into which the fuel burner discharges, heating elements for receiving products of combustion from the combustion chamber, a header to which said heating elements conduct said products of combustion, said casing having a second pair of opposed openings with which said header communicates, a draft regulator and a vent pipe connected to the latter openings respectively, and means for blowing air to be heated through said casing and in heat exchanging relation to said heating elements, said openings being similar in size and shape, and said fuel burner, positioning means, draft regulator and vent pipe each being similarly dimensioned and interchangeably mountable in any one of said openings.

3. Heating means for a unit heater comprising a plurality of tubes, a plenum chamber surrounding said tubes and providing a passageway for air to be heated in heat exchange relationship to said tubes, an open ended combustion chamber selectively movable to alternative positions within said plenum chamber and spaced from the walls thereof, said combustion chamber having openings at its side communicating with said tubes, a burner positioned to discharge fuel axially into one end of said combustion chamber, a target positioned at the opposite end of the combustion chamber for bafliing the discharge from the burner, said burner and said target being interchangeably mounted adjacent opposite ends of said combustion chamber for alternative installations, and means for conducting products of combustion from said tubes to a vent.

4. A unit heater comprising a casing having a pair of identical oppositely disposed openings in the side walls thereof, an open ended combustion chamber selectively located in said casing in alignment with one of said openings, an oil burner having a blast tube extending through one of said openings for directing fuel and air into one end of said combustion chamber, a sleeve surrounding said blast tube and spaced therefrom, said sleeve being closed at its outer end by a mounting flange for the oil burner and being open at its inner end adjacent the combustion chamber to provide a sound muffling chamber about the blast tube of the burner, positioning means for holding the combustion chamber in position adjacent the inner end of said sleeve, heating elements for receiving products of combustion from the combustion chamber, a header to which said heating elements conduct said products of combustion, said casing having a second pair of opposed openings with which said header communicates, a draft regulator and a vent pipe interchangeably connected to the latter openings respectively, and means for blowing air to be heated through said casing and in heat exchanging relation to said heating elements, said openings being similar in size and shape, and said fuel burner, positioning means, draft regulator and vent pipe each being similarly dimensioned and interchangeably mountable in any one of said openings.

5. A unit heater comprising a casing having front and back walls and two opposite side walls, said front wall having an outlet with louvers therein for directing and controlling the passage of air through said casing, said back wall having an inlet formed therein, a blower mounted in the inlet in said back wall, each side wall having a pair of oppositely disposed openings formed therein, a fuel burner positioned adjacent one of said openings, a combustion chamber located within said casing adjacent said fuel burner, positioning means mounted in the opening opposite to said burner and holding said combustion chamber adjacent said burner, heating tubes for receiving the products of combustion from said combustion chamber, a header communicating with said heating tubes and extending between the other two openings in said casing, a draft regulator mounted in the opening at one end of said header, and a vent pipe mounted in the opening at the other end of said header, said openings being of the same size and shape, and said burner, positioning means, draft regulator and vent pipe each being similarly dimensioned and interchangeably mountable in said openings.

References Cited in the file of this patent UNITED STATES PATENTS 315,040 Jones Apr. 7, 1885 1,723,716 Allington Aug. 6, 1929 1,958,331 Bell May 8, 1934 1,994,184 Williams Mar. 12, 1935 2,161,021 DeLin June 6, 1939 2,172,399 Mueller Sept. 12, 1939 2,259,187 Turnbull Oct. 14, 1941 2,302,456 McCollum Nov. 17, 1942 

